One question, several references
Understanding orders of magnitude and zoom
Why a small slider movement can change sizes greatly: reading a logarithmic scale.
Try it in the explorer →Each power of ten changes the scale
An order of magnitude corresponds to a factor of ten. Going from 1 metre to 10 metres and then to 100 metres adds the same interval on a logarithmic scale, while the gaps in metres increase.
A common factor for every image
During zoom, dimensions share a common conversion between metres and pixels. Earlier objects shrink while the next ones enter the view; images must not be independently enlarged to fill the screen.
The small eventually becomes invisible
If an object becomes smaller than a pixel, a silhouette several pixels wide could no longer remain a to-scale depiction. An enlarged marker must therefore be identified separately.
Some intervals contain no familiar object
The guide then gives a ratio and the next reference. Planck length is a theoretical reference: fictitious measured objects are not created to fill the range.
This journey’s references
Sources and method
Dimensions and conventions are those of the fact sheets linked above. Illustrations remain interpretations. Providing a documentary source does not independently certify every catalogue value.